Pavement expansion clip



Oct. 9, 1934. R. c. HOLCOMB 1,976,396

PAVEMENT EXPANS ION CLIP Filed June 26, 1933 2 Sheets-Sheet r INVENTOR: $242.20 6 1% BY flUWM 2L..,

A TTORNEX Oct. 9, 1934- R. c. HOLCOMB 1,976,396

PAVEMENT EXPANSION CLIP Filed June 26. 1933 2 Sheets-Sheet 2 i I v INVENTOR.

C fiolaad C. flazcom ATTORNEY.

Patented Oct. 9, 1934 UNITED STATES PATENT OFFICE I 8 Claims.

This invention relates to concrete road paving and has particular reference to means for supporting expansion strips for such pavement prior to and during the operation of pouring and tamp-.

5 ing the concrete for such pavement.

The methods customarily employed, at least in the State of California, consist in dividing a roadbed crosswise into sections, each about ten feet wide. There is provided, in each section and about lfljsixty feet apart, a series of transversely positioned expansion strips to permit each sixty foot stretch of concrete freely to expand and contract. Experience in this State has taught that a strip of suitable, resilient material, about onelilhalf inch thick, is sufficient to take care of all such variations. It has also been found that practically all such expansive variations take place lengthwise, in the direction of the vehicle traflic, and not crosswise.

In practice, parallel forms, in the shape of planks set on edge, are first placed along the roadway, ten feet apart. Transversely between these forms and sixty feet apart, are placed the expansion strips. After one continuous stretch of ten foot wide sections has been poured, tamped and allowed to set, the forms are removed. The adjacent stretch of sections is then ready for pouring, and it is now found that the sections on the near side are bordered by the newly poured concrete and on the far side by another line of forms. The expansion strips are now to be placed between this new pavement and the forms. When the pouring is started from botlf sides of the roadway, the last series of expansion strips may be set between two walls of new concrete.

With these conditions in view, the object of my invention is to provide means for supporting such ble not only of locating the expansion strips but.

also of holding them firmly in position both horizontally and vertically during the pouring and tamping of the concrete.

These and the further objects and important novel features of my invention are hereinafter fully explained and illustrated in the appended drawings, of which:

. right of Fig. 5, which latter view shows one clip Fig. 1 is a front elevation of a structure embodying the invention, a

Fig. 2 is a substantially corresponding frontview showing the structure of my invention mounted on a form and supporting a pavement expansion strip,

Fig. 3 is a plan view of the device substantially in agreement with the foregoing Fig. 4 is a plan view showing the structure of my invention imbedded into concrete pavement and supporting a second structure in position to i hold an expansion-strip, and 7 Fig. 5 is a view taken transversely through a; roadbed and showing my device supporting an expansion strip.

The device of my invention is a box shaped structure comprising a back, plate 1, from which project side flanges 2 and 3 to form an elongated trough closed at the bottom by an end wall 4. This trough is of a size to receive the end of an I6 expansion strip E, such as above referred to. The side flanges extend upward to form two'ears 5, 6 which, after the expansion strip is seated, are folded over each other and over the top of this strip, as shown in Fig. 2, to complete the box designed to support the end of the expansion stripboth horizontally and vertically.

Following now the preliminary explanation above given,I show, in Fig. 5, a fragment of a partly completed roadway. One stretch of sections, C, is already completed and the form on its left edge has been removed. Another form, F, is shown at the edge of the adjacent stretch of sections to be poured. The clip of my invention is here shown set in the ground with its back 90 against the side of the form F, and it is for this purpose made with a downwardly extending back portion 7, which is suff ciently pointed readily to' enter the ground. The bottom plate 4 is shown" made with wings 8, which serve to locate the device vertically by coming to rest on the top surface of the ground. At the top,'the back plate may terminate in a, 1ip,9, which is bent over the form and fastened thereto by driving a tack through the hole in the lip. I v

I Afterpouring and tamping, the form ispulled away and the clip remains lodged in the concrete to form a permanent part of the pavement. This condition is best shown in Fig. 4 and at the set up against a form and opposed to it, a clip which has been molded into the finished stretch of concrete. Against the back of this imbedded clip, it now becomes necessary to mount an adno ditional clip, back to back, and this is readily done by merely pushing this new clip into the ground against the imbedded clip. In the ears 5 and 6 may be placed elongated perforations 12,

6 which will be brought into registration when these lips are folded over the supported expansion strip and in line with the perforation 9 of the imbedded clip. A tack may be driven through these alined holes into the expansion. strip to hold 10 the top of this new clip in position relative to the imbedded clip. Should it, however, be foundedvisable to add additional devices for more securely fastening the clip in position, it may be done by placing perforations 13 in the backplate which,

15 by means of tacks driven through these holes,

may be fastened to the form. After the. formais removed, such tacks will be found imbedded in the concrete with their pointed end projecting. The

second clip, when it is seated on the imbedded clip,

as aforesaid, may be located by meansrof these projecting tacks.

From the foregoing it is seeng'that-it is not only aproblemof mounting a clip against a wooden I form,but even more important to provide'means 5 for mounting the clipagainst an imbedded clip and to use this imbedded clip fort-locating and supporting" this -second clip, no other locating means being available. It is suggested to make the clips for mounting against the wooden form 6 with sharp conical extrusions 16, as shown in- Figs.

4 and 5inplace of the plain perforations 13.. Such extrusions can readily be. made when the clip is first formed; theycan be driven into the wood of the form and,:when the'latter is stripped away,

85 will project to provide perfect guides for the second clip, which: then maybe made with plain holes 13,.or. the extrusions of the first may extend intoztheextrusions of thesecond. Ablow with a hammer. will. flattenthese conical tips against 4 5 the surface of the: second clip to hold it firmly in correct; position. :This: ismerely illustrativeaof onerway to mount a second clip on an .imbedded;

clip. Other more; suitable. means ;may suggest themselves.

Referring to Fig... 1, it is noticed .that the back plate 1 is shown vertically. slit at 14,.intermediate the said side flanges 2 and 3. This'isdoneinorder that the clip may adjust itself to the expansive and contractive movements of the pavement. .3 The ears 5 and. 6 overlap and also-permit freedom of suchmovement. -The.bottom-;plate'4'is also shown produced by means of overlapping ears but, exceptfor'convenience;inmanufacture, there is no'need of such separation of the bottom plate 5 .3 asthe expansive variation at thebottom is negligible.- The slit14 is not centrally located in the trough, but is set a little to one side. vThe advantageof this-is,.that these-slits-donot coincide when two clips are placed back to back, as shown :in Fig- 4, but overlap, thereby insuringa perfect seal. As stated, thev expansivemovement of the pavement, transversely, isnegligible. For this reason,..itis possible for the seated expansion strip to extend to the .back of the clip and, when 2 the clips are set and tightly held. back to back and the slits 14. overlap, there is no chance for dirt and grit to work its waybetween the clipsand between the expansion strips'and the clips. This is .very "important andmustv be carefully .noted. l Evena smallamount of dirt orgrit working its way between the ,clipandthe expansion strip, when the concrete is relatively cold,.will suffice to crack the pavement whentheconcrete expands in rising temperature. the most important feature of my invention.

poured and tamped. Their solid top becomes compressed when the concrete expands and, being unable again to spread when the concrete contracts, they prevent the expansion strips from expanding. A gap is thereby opened between the clips and the encasing concrete, into which grit and gravel is free to drop.

By means of my tightly fitting, perfectly locating and firmly supporting, resilient clip these difficulties are overcome and an important step in the art effected.

I claim:

1. In concrete paving, a clip-for supporting a pavement expansion strip, said clip comprising a back plate seatable against a form and having a pointed end for insertion into the ground and an open top U-shaped, flange projecting from said back and shaped fittingly to hold the end of such strip, said flange terminating at the top in two lips of a size to be folded over the top of the strip to lock the strip firmly in position.

2. In concrete paving, a clip for supporting a pavement expansion strip, said clip comprising a back plate seatable against a form and having a pointed end for insertion in the ground and an open U-shaped flange projecting from said plate andshaped to receive the end of such strip, said flange terminating at the topin two lips of a size to be folded over the top of said strip to lock the strip firmly in position, the-back plate being' slit intermediate the sides of said flange to-permit contractive andexpansive movement of the strip within the clip.

3. A clip for supporting a pavement expansion member, said clip comprising a flat body from which projects parallel side flanges and a con-- necting bottom flange, the side flanges being at the top made with lips shaped to be folded over the top of such expansion member after it has been seated within the flanges for the purpose of locking said member in position.

4. In concrete road paving, the combination with forms set parallel on the ground, of a pair of clips, each having a flat back seatable against said forms and pointed at the bottom for insertion in the ground, there being a flat horizontal base projecting from said back to rest on the ground when the clip is inserted and parallel flanges rising from said base and spaced to admit the end of an expansion member, said flanges terminating at the top in lips foldable over the top of said member to lock the member firmly in position. I

5. In concrete road paving, a clip for supporting the end of an expansion member, said clip being made with flanges encompassing the end of said. member, said clip being capable of sidewise expansive movement at the top to adjust itself to the expansive movement of said member. 6. In concrete road pavement, a clip for holding the end of an expansion member, said clip and member becoming embedded in the concrete. of the pavement in such position that the back of the clip becomes flush with the exposed edge of the pavement after the forms are removed, there 1'50 in the latter by means of a nail driven through the perforation of said lip and the latter clip into the expansion member seated therein.

8. A concrete pavement clip shaped to be pushed into the ground against a fiat base projecting from the body of the clip and made with flanges rising from said base and spaced to admit an expansion member, said flanges being shaped at the top to be folded over the top of said member.

ROLAND C. HOLCOMB. 

